On macOS, it is as simple as brew upgrade fnm. On other operating systems, upgrading fnm is almost the same as installing it. To prevent duplication in your shell config file, pass --skip-shell to the ...

# fulldouble: Use double buffering in fullscreen. It can reduce screen flickering, but it can also result in a slow DOSBox-X. # fullresolution: What resolution to use for fullscreen: original, desktop ...